Quick update of how I got on...

Rough idle/stalling returned a day after it went away so unplugged the MAF (again ran fine with unplugged) and drove to imparts clayton. brand new Bosch sensor was $250 incl. GST. Took the hit and replaced. 5 minute job and since then have done over 200km without incident and economy has been great.

So long story short... timing belt/water pump/coolant replacement triggerred thermostat to die... thermostat/temp sender replacement triggerred MAF to die.. I replaced MAF myself and all is well. No idea how each relates to the other but after this I'll be finding a new mechanic. $400 over budget on original plan of timing belt job but just glad the car is running better than ever!

Thanks to those who replied especially Jmac. spot on "internet diagnosis" that saved me a heap of time/wasted money.

Cheers!